There are the national roads (riksvägar) that have two digit numbers. They are the next best roads.

The three digit numbered roads (länsvägar) come in two flavors. The big ones (numbers 100-400) and really small ones (all other numbers).

The European roads and the national roads are very well marked with signs telling you what road you are on and how to get onto these roads. The three digit numbered roads with numbers up to 400 are also marked. Roads with lower numbers are situated south of the roads with higher numbers.

The small ones, and in some cases 4 digit roads that might show up on your GPS map are never marked with their numbers. They are just numbered for some administrative purpose and the numbers cannot be used while driving.

Finding Directions

The best markings are made with big blue signs with the name of the upcoming towns.
If the road leading there is a freeway, the signs are green instead of blue.
Unless you are going on a very big road, make your directions based on what towns or villages you are passing and keep an eye out for these signs instead of the road numbers.

Speed Limits

The current speed limit is very well marked by signs. The speed limit signs are in km/h. The signs you see are normally 30, 50, 70, 90, 110 and occasionally 120 (there is only one road with a 120km/h limit). Two speed signs on each side of the road mean from this point this is the new speed. One sign on the right means that this is the speed on this road but there is no change in speed.

Since 2001 some new signs have been introduced or have been altered to also indicate the speed limit. These are:

The Freeway (Motorväg) sign now also means 110km/h.

The Highspeed road (Motortrafikled) sign indicates 90km/h.

The new start of village sign means 50km/h.

The new end of village sign means 70km/h.

The respect for obeying the speed limit is rather poor.
Often, when you driving at the correct speed on a 70 or 90km/h road you will constantly get passed by other cars or be urged to get out of the way to let them pass.

You are obliged by law to have your headlights on at all times, even in the middle of the day. Modern Swedish-sold cars always have the lights turned on automatically (unless you actively turn it off), so if you rent a car in Sweden you won't have to worry about it.

Hazards

Wild animals! The biggest roads normally have fences against wild animals, but the smaller roads do not. You need to look out for deer and moose - a moose collision in particular is very dangerous and often kills instantly. In the north you will also have to watch out for reindeer.

Be extra careful to wild animals on the roads under these circumstances:

Sunrise/sunset.

Springtime (as moose reject last year's calves and give birth to new ones).

Moose hunting season in early October.

Edge of forests.

Bridges across streams.

In some cases there are fences along part of the road and then the fences stop for the purpose of letting the animals pass. In such cases and in other places where wild animals are often seen there are normally warning signs.

These animals are mostly moving at dusk and dawn. While driving along lakes be especially observant as animals go for drinks at the lakes. Also, if driving in the September hunting season, the wild animals might be scared by hunting parties and move around more than usual.

If you hit an animal and it wanders off into the woods wounded, don't forget to mark the spot where it wandered into the forest. Your car should be fitted with a special paper ribbon for this purpose. The purpose for this is to be able to use dogs to hunt down the wounded animal.